[PATCH] D94040: [WebAssembly] Update basic EH instructions for the new spec

[Heejin Ahn via Phabricator via llvm-commits]

aheejin created this revision.
aheejin added reviewers: dschuff, tlively.
Herald added subscribers: wingo, ecnelises, mgrang, sunfish, hiraditya, jgravelle-google, sbc100.
aheejin requested review of this revision.
Herald added a project: LLVM.
Herald added a subscriber: llvm-commits.

This implements basic instructions for the new spec.

- Adds new versions of instructions: `catch`, `catch_all`, and `rethrow`
- Adds support for instruction selection for the new instructions
  - `catch` needs a custom routine for the same reason `throw` needs one, to encode `__cpp_exception` tag symbol.
- Updates `WebAssembly::isCatch` utility function to include `catch_all` and Change code that compares an instruction's opcode with `catch` to use that function.
- LateEHPrepare
  - Previously in LateEHPrepare we added `catch` instruction to both `catchpad`s (for user catches) and `cleanuppad`s (for destructors). In the new version `catch` is generated from `llvm.catch` intrinsic in instruction selection phase, so we only need to add `catch_all` to the beginning of cleanup pads.
  - `catch` is generated from instruction selection, but we need to hoist the `catch` instruction to the beginning of every EH pad, because `catch` can be in the middle of the EH pad or even in a split BB from it after various code transformations.
  - Removes `addExceptionExtraction` function, which was used to generate `br_on_exn` before.
- CFGStackfiy: Deletes `fixUnwindMismatches` function. Running this function on the new instruction causes crashes, and the new version will be added in a later CL, whose contents will be completely different. So deleting the whole function will make the diff easier to read.
- Reenables all disabled tests in exception.ll and eh-lsda.ll and a single basic test in cfg-stackify-eh.ll.
- Updates existing tests to use the new assembly format. And deletes `br_on_exn` instructions from the tests and FileCheck lines.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D94040

Files:
  llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
  llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCTargetDesc.h
  llvm/lib/Target/WebAssembly/WebAssemblyCFGStackify.cpp
  llvm/lib/Target/WebAssembly/WebAssemblyISD.def
  llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
  llvm/lib/Target/WebAssembly/WebAssemblyInstrControl.td
  llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.td
  llvm/lib/Target/WebAssembly/WebAssemblyLateEHPrepare.cpp
  llvm/lib/Target/WebAssembly/WebAssemblyRegStackify.cpp
  llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
  llvm/test/CodeGen/WebAssembly/cfg-stackify-eh.ll
  llvm/test/CodeGen/WebAssembly/eh-labels.mir
  llvm/test/CodeGen/WebAssembly/eh-lsda.ll
  llvm/test/CodeGen/WebAssembly/exception.ll
  llvm/test/MC/WebAssembly/annotations.s
  llvm/test/MC/WebAssembly/basic-assembly.s
  llvm/unittests/Target/WebAssembly/WebAssemblyExceptionInfoTest.cpp

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